Testing the 9V Battery Hack (or: Assault on Battery) – xkcd
9 Volt Batteries Contain 6 AAAA Batteries | Broken Secrets
Amazon.com: Duracell - CopperTop 9V Alkaline Batteries - long lasting, all-purpose 9 Volt battery for household and business - 4 count : Sports & Outdoors
Rechargeable 9 Volt Lithium Polymer Battery | Battery Mart
How to Get 6 AAAA batteries from a 9V battery « Hacks, Mods & Circuitry :: Gadget Hacks